Low turn-over bone disease in patients with chronic renal disease.

During the last decades, the prevalence of various types of renal osteodystrophy has been changed from a high to low bone turnover. Besides the established conventional risk factors, the existence of a dynamic bone disease as most prevalent form of renal osteodystrophy nowadays and its reduced ability to handle an exogenous calcium load has implied a higher risk for vascular calcification, morbidity and mortality in the dialysis population. Calcium-based phosphate binders are inexpensive and efficient but their extended and/or inappropriate use, particularly when used in combination with vitamin D analogues, may contribute to the development of adynamic bone disease and promotion of soft-tissue and vascular calcification. It seems reasonable to reduce the number of calcium carbonate/acetate tablets to only 1 g/day in order to increase serum phosphate and decrease serum calcium, which both in turn might positively stimulate the parathyroid hormone secretion. Low calcium dialysate (1.25 mmol/l) was reported to have an impact on the evolution towards markers reflecting higher bone turnover, most probably by prevention of a positive calcium balance, enabling sustained stimulation of parathyroid hormone secretion. Hence, the two reasonable strategies should be employed together in order to prevent consequences related to adynamic bone disease and to contribute to a better long-term quality of life and survival of dialysis patients.